Add-on resting respirometry system


Resting Respirometry System Add On Horizontal
Resting Respirometry System Add On Horizontal

More info coming soon.


This add-on resting respirometry system includes 4 additional horizontal chambers and all required accessories for your core resting respirometry system.


This is product data for the selected system:


These products are included in the system:


PowerX4 (LAN/Bluetooth power strip-230V/50Hz)
Powerx4 ISO (1)

Use this industrial grade 4-fold power strip for software-driven control and monitoring of equipment via LAN/Ethernet or Bluetooth.

Connect pumps, solenoid valves, or stirrers to one of four independent electrical sockets switching at zero current (ZCS), e.g., for automated respirometry, water quality regulation, shuttle box experiments etc.

Electrical parameters like input voltage and power consumption (in Amps) for each relay, can be monitored and logged in Loligo® software for diagnostics of connected appliances.

Witrox 4 oxygen meter for mini sensors (4xO₂/1xtemp)


  • Real-time compensation for temperature, salinity and barometric pressure
  • Measure oxygen in: % air saturation, % oxygen saturation, kPa, Torr, mg/L, mmol or ml/L.
  • Unbeaten precision and stability with mini optodes
  • Measure oxygen in both liquid and gas phase
  • No oxygen consumption by sensor
  • Immune to electrical and magnetic interference
  • Oxygen sensing based on luminescence lifetime detection
  • Wide variety of mini sensors available
  • Excellent long-term stability
  • Multiple instruments systems - use up to 7 instruments with a single PC 
  • Minimum footprint


Witrox 4 is a four-channel oxygen instrument for use with fiber optic mini sensors (optodes). It has a build-in Bluetooth transmitter for wireless PC communication, and includes a high accuracy temperature sensor and software for compensation of oxygen data to changes in temperature, salinity or barometric pressure in real-time.

We developed Witrox 4 for the most challenging environments and applications. The wireless Bluetooth 2.0 communication allows you to keep that vulnerable PC/Notebook at a distance avoiding hazards like water or blood. Also problems associated with USB and serial communication are avoided, and the rugged compact design offers excellent protection and take up minimum bench space. 
The instrument comes with easy-to-use software for Windows, and a 4-wire Pt1000 temperature sensor (Class B 1/3 DIN) with +/- 0.15 °C accuracy for 5-digits real-time compensation of oxygen data.

A PC computer with Bluetooth 2.0 or higher (build-in or dongle) is required for operation.

How does it work?

The instrument LEDs emit blue-green light that excites the oxygen mini sensor (optode) to emit fluorescence. If the oxygen sensitive dye encounters an oxygen molecule, the excess energy is transferred to the oxygen molecule in a non-radiative transfer, decreasing or quenching the fluorescence signal. The degree of quenching correlates to the partial pressure of oxygen inside the dye matrix, which is in dynamic equilibrium with oxygen in the sample. The decay time measurement is internally referenced.

For more details and a diagram on this measurement principle go to our FAQ.


Included with the Witrox 4


Sensor spots, 10 pcs (3mm/non-autoclavable)
Sensor Spots


  • Excellent long-term stability
  • Easy to handle and robust
  • Non-invasive and non-destructive measurement from outside through the wall of the flask
  • Usable for process application
  • No self-consumption of oxygen
  • Signal independent on flow velocity
  • Insensible towards electrical interferences and magnetic fields
  • Measures oxygen in liquids as well as in gas phase
  • Excellent mechanical stability and long-term stability
  • Online monitoring


Sensor spots are thin planar oxygen mini sensors immobilized onto either polyester or glass supports, for use with our Witrox instrument (i.e., not compatible with microplate readers!).

The sensor spots are glued inside chambers, flasks or disposables with translucent and non-fluorescent walls (e.g. glass, polyester, acrylic etc.). Then oxygen measurements can be done in a non-invasive and non-destructive way from outside and through the wall of your vessel.

With silicone glue you can glue the sensor spots inside your own chambers, flasks, disposables, or we can do it for you.

To use the sensor spots a fiber optic instrument and an external fiber cable (light guide) is required. The tip of the fiber cable delivers (blue) light to the backside of the sensor spot though the wall (and transparent glue). The front side of the sensor spot is in contact with the media (liquid or gas), e.g. the light is not passing through the media.

There are two ways of fixing the (external) fiber cable over the centre of the (internal) sensor spot:

1) A bare tip fiber cable is fixed with a special chamber (holder), or run through a Radiometer/Cameron dummy electrode adapter for fiber optic oxygen sensing in Radiometer/Cameron electrode chambers, cuvettes etc.

2) A fiber cable with a threaded SMA connector at the tip is screwed onto a fitting sitting on a velcro band adapter for curved chamber walls or planar walls.


Silicone glue for sensor spots
Dow Corning Silicone Glue


  • One-component adhesive/sealant
  • Easy to apply
  • Cures (to a tough, flexible rubber) at room temperature when exposed to moisture in the air
  • Good adhesion to many substrates
  • Acetoxy cure system
  • Stable and flexible from -60 ºC to +180 ºC (-76 ºF to +356 ºF), with short peaks up to +205 ºC (401 ºF)
  • Excellent dielectric properties
  • Complies with MIL-A-46106
  • Complies with FDA 177.2600


We offer this clear and non-toxic silicone adhesive for mounting sensors spots on many substrates such as glass and most common engineering plastics. Suitable solvents include isopropyl alcohol, acetone or methyl ethyl ketone.

On exposure to moisture, the freshly applied material will "skinover" in ~7 min. Any tooling should be completed before this skin forms. After skin formation, cure continues inward from the surface. In 24 hours (at room temperature and 50 % relative humidity) the silicone glue will cure to a depth of about 3 mm.

For instructions on how to mount a sensor spot, please go to our FAQ.

Fiber cable (bare tip)
Fiber Cable Bare Tip

A polymer optical fiber is needed as a light guide between the fiber optic instrument and the sensor spots.

Glass chambers

Glass chamber (Horizontal/ID9/L20)


  • Borosilicate glass materials to avoid O2 storage/release
  • Ground glass joint stopper for 100 % gas and water tight chamber
  • 2 x 2 ports for intermittent flow respirometry
  • For use in both full strength sea water and fresh water
  • Easy tool-free handling and cleaning
  • Optional replacement tubes for shorter/longer chambers


These tube-shaped borosilicate glass chambers are designed for measurements of oxygen consumption rates in resting/inactive aquatic organisms (e.g., fish or inverts), and have ports for intermittent respirometry.

The ground glass joint stopper makes for a gas and water tight seal, and can be combined with tubes with similar inner diameter (ID) but different lengths to get a range of volumes/sizes.

Adapter rings for glass chambers (9mm)
Adapter Rings 1 Low

These adapter rings (set of four rings) can be used to fix mini chamber (horizontal) and/or mini chamber (vertical) in our water bath for mini chambers.

Holder for glass chambers (horizontal)
Holder For Glass Chambers Horizontal

Use this holder with up to four horizontal glass chambers ID 9-28 mm.

To hold chambers of different dimensions, we offer adapter rings that matches the outer diameter of each available chamber.

The holder can be mounted inside a water bath for thermostatic control.

For each chamber, there is a fixture for an external fiber optic cable required for oxygen or pH sensor spots.

Water bath for glass chambers (horizontal)
Mini Chamber Water Bath Without Holder

This acrylic water bath (L400 x W225 x H140 mm) for one of our horizontal mini chamber holders, comes with a lid and ½" fittings for running thermostatic water through it.


Miniature DC pump (50-1500mL/min)
Mini DC Pump Front


  • DC power operated
  • Brushless drive motor
  • Quiet pulseless flow
  • Stainless materials


This tiny impeller pump is highly efficient despite the compact design allowing for installation into the smallest places. We have chosen acetal inner parts and impeller, viton seals, and a stainless steel housing so that the pump can be used in hostile environments like marine labs.

Pump flow rate can be adjusted by varying input voltages between 5 VDC and 12 VDC. Further fine tuning can be made by restricting the outgoing flow with a tube clamp or by using a thinner tube thereby increasing friction against flow. 

This flange pump mounts onto any planar surface with stainless screws and o-rings (both included). We can supply an optional fitting flange with barb hose fittings for 3.2 mm tubing, but the pump is NOT made for submerged use!

DC power adapter


  • Compact DC power adapter for miniature DC pumps
  • Adjustable voltage: 3, 4.5, 5, 6, 9, and 12 V
  • Waterproof (IP67) M9 connector 
  • Connects to Schuko (EU) outlets

This compact and efficient DC power adapter is intended for use with our miniature DC pumps. The voltage is adjustable from 3, 4.5, 5, 6, 9, and 12 V, and the special M9 connector is waterproof (IP67) for improved ruggedness. The power adapter fits standard Schuko (EU) outlets, e.g., in our PowerX4 Bluetooth/LAN power strips.

Note: The miniature DC pump operates from ≥ 5 V.


Tygon Chemical (2001) tubing, per metre (ID1.59mm),L/S14,1/16”
Tygon Chemical (2001) Tubing, ID 1 59 Mm End


  • Best chemical resistance of any Tygon® formulation
  • Plasticizer-free
  • Transparent for easy flow monitoring
  • Low gas permeability


Genuine Masterflex© Tygon Chemical (2001) tubing with low gas permeability and excellent chemical resistance. The tubing is clear for easy flow monitoring, and can be sterilized using autoclaving, ethylene oxide or gamma irradiation.

Tygon Chemical (2001) tubing, per metre (ID3.14mm),L/S16,1/8”
Tygon Chemical (2001) Tubing, ID 3 14 Mm End


  • Best chemical resistance of any Tygon® formulation
  • Plasticizer-free
  • Transparent for easy flow monitoring
  • Low gas permeability


Genuine Masterflex© Tygon Chemical (2001) tubing with low gas permeability and excellent chemical resistance. The tubing is clear for easy flow monitoring, and can be sterilized using autoclaving, ethylene oxide or gamma irradiation.


Stainless tube connector (OD 2.00 x L100 mm)
Steel Tube Connector

A stainless tube connector for temperature control.


These products are optional for the selected system:


Powerx4 ISO (1)
Refrigerated Circulating Bath
Refrigerated Circulating Bath


Gas control set
Temperature control set


These files can help you with the selected system: